I am designing an open source dive computer and have been looking for the simplest way of managing the battery which consists of three functions: 1) managing the charging of the battery 2) Regulating the output to 3.3v 3) providing accurate battery level to the processor (gas gauge).

I have not found any solutions that can do all this in one chip or for that matter, less than three (one for each of these functions). Does anyone know of a good, simple solution? I want the device to worn on the wrist so board space is at a premium. So far I am looking at Microchip's MCP73831 for charging, the TI's TPS61201 for regulating and TI's BQ27000 for "gas gauge" functionality. If you can point me in a better direction, I would appreciate it!